1. Field of the Invention
The present invention relates to a vehicular seat hinge arrangement suitable for use in an automotive vehicle seat of the category of seat which includes a hinged seat cushion and a separately hinged seat back.
More specifically, the present invention relates to seat hinge arrangement suitable for use as, for example, the rear seat of an automotive vehicle and which is operable between a position in which it functions to accommodate a passenger of the automotive vehicle and an "escaped" position wherein the space within the vehicle normally occupied by the vehicular seat when it is in its riding position is made available for other purposes such as storage. Still more specifically the present invention seeks to provide a vehicular seat which is operable between its riding position, an intermediate "stacked" position, and its escaped position without any need on the part of the user for unlocking operations, and which can be maintained stably in any of the above riding, stacked, or escaped positions without the user having to carry out locking operations with respect to the hinge mechanism.
2. Description of the Prior Art
A known seat cushion arrangement invented prior to the present invention, is exemplified in JP-B2-57-22768.
In the above referenced publication, a car body connector hinge link, which is provided for anchoring a seat back cushion to the body of an automobile, has a pivot point defined at its lower portion. About this pivot point, the connector link is designed to pivot between a horizontal position and a vertical position.
At its upper side the bracket comprises a shaft by which it is pivotably connected, at a pivot point defined at the lower portion of the seat back, to the connector link. At its middle portion, the connector link comprises a bolt type stopper which is movable upwardly and downwardly.
When moved downwardly, the stopper cooperates with a groove defined in a portion of a cam member defined at the car body side of the connector link for maintaining the connector link in a predefined vertical position from which it may not fall forward.
By means of inserting the bolt type stopper into a groove or notch defined in a cam formed at the boss portion of the seat back, the seat back is restrained from falling forward relative to the connector link. In this way the seat back is, in effect, rigidly connected to the connector link which in turn pivots at the car body side of the bracket.
In the above disclosed arrangement, when the seat back is to be pivoted forward from it's standing position so as to occupy its "stacked" position, in which it lays over the lower seat cushion, the bolt or stopper must be removed from the groove defined in the cam member at the body side of the bracket in order to release the seat back mechanism after which the seat back may be pivoted forward.
When the seat back is to be pivoted forward so as to lie directly on the floor of the vehicle, and thus to occupy the space from which the seat cushion has been escaped, the stopper must be removed from the lower groove in order to allow the link to fall forward so that the seat back may lay directly on the floor of the vehicle.
It will be noted that in the above system problems exist that the stopper must be manipulated differently if the seat back is to be pivoted forward so as to rest on the seat cushion than if it is to be pivoted all the way forward so as to rest directly on the floor of the vehicle which is normally occupied by the seat cushion. This is troublesome and time consuming for the user. What is more, the construction of the above described connector link is rather complex, and therefore accordingly it is rather expensive to produce.